#pragma once

#include "Math_Common.h"
#include "Math.h"

namespace framework
{
	namespace math
	{
		/** Standard 2-dimensional vector.
			@remarks
				A direction in 2D space represented as distances along the 2
				orthogonal axes (x, y). Note that positions, directions and
				scaling factors can be represented by a vector, depending on how
				you interpret the values.
		*/
		class MATH_API Vector2
		{
		public:
			Real x, y;

		public:
			inline Vector2()
			{
			}

			template<typename T>
			inline explicit Vector2(const T& o )
			{
				x = o.x;
				y = o.y;
			}

			inline Vector2(const Real fX, const Real fY )
				: x( fX ), y( fY )
			{
			}

			inline explicit Vector2( const Real scaler )
				: x( scaler), y( scaler )
			{
			}

			inline explicit Vector2( const Real afCoordinate[2] )
				: x( afCoordinate[0] ),
				  y( afCoordinate[1] )
			{
			}

			inline explicit Vector2( const int afCoordinate[2] )
			{
				x = (Real)afCoordinate[0];
				y = (Real)afCoordinate[1];
			}

			inline explicit Vector2( Real* const r )
				: x( r[0] ), y( r[1] )
			{
			}

			template <typename T> T& force_cast()
			{
				char t[sizeof(T)==sizeof(*this)?1:0]={0};
				return reinterpret_cast<T&>(*this);
			}
			template <typename T> const T& force_cast()const
			{
				char t[sizeof(T)==sizeof(*this)?1:0]={0};
				return reinterpret_cast<const T&>(*this);
			}

			template <typename T>
			Vector2& from (const T& src)
			{
				x=src.x;
				y=src.y;
				return *this;
			}
			template <typename T>
			T& to(T& t)const
			{
				t.x=x;
				t.y=y;
				return t;
			}

			/** Exchange the contents of this vector with another. 
			*/
			inline void swap(Vector2& other)
			{
				std::swap(x, other.x);
				std::swap(y, other.y);
			}

			inline Real operator [] ( const size_t i ) const
			{
				CCASSERT( i < 2 , "Vector2 only 2 items!" );

				return *(&x+i);
			}

			inline Real& operator [] ( const size_t i )
			{
				CCASSERT( i < 2 , "Vector2 only 2 items!" );

				return *(&x+i);
			}

			/// Pointer accessor for direct copying
			inline Real* ptr()
			{
				return &x;
			}
			/// Pointer accessor for direct copying
			inline const Real* ptr() const
			{
				return &x;
			}

			/** Assigns the value of the other vector.
				@param
					rkVector The other vector
			*/
			inline Vector2& operator = ( const Vector2& rkVector )
			{
				x = rkVector.x;
				y = rkVector.y;

				return *this;
			}

			inline Vector2& operator = ( const Real fScalar)
			{
				x = fScalar;
				y = fScalar;

				return *this;
			}

			inline Vector2& operator = ( const cocos2d::Point& pt)
			{
				x = pt.x;
				y = pt.y;

				return *this;
			}
			operator cocos2d::Point() const
			{
				return cocos2d::Point(x,y);
			}

			inline bool operator == ( const Vector2& rkVector ) const
			{
				return ( x == rkVector.x && y == rkVector.y );
			}

			inline bool operator != ( const Vector2& rkVector ) const
			{
				return ( x != rkVector.x || y != rkVector.y  );
			}

			// arithmetic operations
			inline Vector2 operator + ( const Vector2& rkVector ) const
			{
				return Vector2(
					x + rkVector.x,
					y + rkVector.y);
			}

			inline Vector2 operator - ( const Vector2& rkVector ) const
			{
				return Vector2(
					x - rkVector.x,
					y - rkVector.y);
			}

			inline Vector2 operator * ( const Real fScalar ) const
			{
				return Vector2(
					x * fScalar,
					y * fScalar);
			}

			inline Vector2 operator * ( const Vector2& rhs) const
			{
				return Vector2(
					x * rhs.x,
					y * rhs.y);
			}

			inline Vector2 operator / ( const Real fScalar ) const
			{
				CCASSERT( fScalar != Real_Zero , "/ zero!" );

				Real fInv = Real_One / fScalar;

				return Vector2(
					x * fInv,
					y * fInv);
			}

			inline Vector2 operator / ( const Vector2& rhs) const
			{
				return Vector2(
					x / rhs.x,
					y / rhs.y);
			}

			inline const Vector2& operator + () const
			{
				return *this;
			}

			inline Vector2 operator - () const
			{
				return Vector2(-x, -y);
			}

			// overloaded operators to help Vector2
			inline friend Vector2 operator * ( const Real fScalar, const Vector2& rkVector )
			{
				return Vector2(
					fScalar * rkVector.x,
					fScalar * rkVector.y);
			}

			inline friend Vector2 operator / ( const Real fScalar, const Vector2& rkVector )
			{
				return Vector2(
					fScalar / rkVector.x,
					fScalar / rkVector.y);
			}

			inline friend Vector2 operator + (const Vector2& lhs, const Real rhs)
			{
				return Vector2(
					lhs.x + rhs,
					lhs.y + rhs);
			}

			inline friend Vector2 operator + (const Real lhs, const Vector2& rhs)
			{
				return Vector2(
					lhs + rhs.x,
					lhs + rhs.y);
			}

			inline friend Vector2 operator - (const Vector2& lhs, const Real rhs)
			{
				return Vector2(
					lhs.x - rhs,
					lhs.y - rhs);
			}

			inline friend Vector2 operator - (const Real lhs, const Vector2& rhs)
			{
				return Vector2(
					lhs - rhs.x,
					lhs - rhs.y);
			}
			// arithmetic updates
			inline Vector2& operator += ( const Vector2& rkVector )
			{
				x += rkVector.x;
				y += rkVector.y;

				return *this;
			}

			inline Vector2& operator += ( const Real fScaler )
			{
				x += fScaler;
				y += fScaler;

				return *this;
			}

			inline Vector2& operator -= ( const Vector2& rkVector )
			{
				x -= rkVector.x;
				y -= rkVector.y;

				return *this;
			}

			inline Vector2& operator -= ( const Real fScaler )
			{
				x -= fScaler;
				y -= fScaler;

				return *this;
			}

			inline Vector2& operator *= ( const Real fScalar )
			{
				x *= fScalar;
				y *= fScalar;

				return *this;
			}

			inline Vector2& operator *= ( const Vector2& rkVector )
			{
				x *= rkVector.x;
				y *= rkVector.y;

				return *this;
			}

			inline Vector2& operator /= ( const Real fScalar )
			{
				CCASSERT( fScalar != Real_Zero , "/ zero!"  );

				Real fInv = Real_One / fScalar;

				x *= fInv;
				y *= fInv;

				return *this;
			}

			inline Vector2& operator /= ( const Vector2& rkVector )
			{
				x /= rkVector.x;
				y /= rkVector.y;

				return *this;
			}

			/** Returns the length (magnitude) of the vector.
				@warning
					This operation requires a square root and is expensive in
					terms of CPU operations. If you don't need to know the exact
					length (e.g. for just comparing lengths) use squaredLength()
					instead.
			*/
			inline Real length () const
			{
				return Math::Sqrt( x * x + y * y );
			}

			/** Returns the square of the length(magnitude) of the vector.
				@remarks
					This  method is for efficiency - calculating the actual
					length of a vector requires a square root, which is expensive
					in terms of the operations required. This method returns the
					square of the length of the vector, i.e. the same as the
					length but before the square root is taken. Use this if you
					want to find the longest / shortest vector without incurring
					the square root.
			*/
			inline Real squaredLength () const
			{
				return x * x + y * y;
			}
			/** Returns the distance to another vector.
				@warning
					This operation requires a square root and is expensive in
					terms of CPU operations. If you don't need to know the exact
					distance (e.g. for just comparing distances) use squaredDistance()
					instead.
			*/
			inline Real distance(const Vector2& rhs) const
			{
				return (*this - rhs).length();
			}

			/** Returns the square of the distance to another vector.
				@remarks
					This method is for efficiency - calculating the actual
					distance to another vector requires a square root, which is
					expensive in terms of the operations required. This method
					returns the square of the distance to another vector, i.e.
					the same as the distance but before the square root is taken.
					Use this if you want to find the longest / shortest distance
					without incurring the square root.
			*/
			inline Real squaredDistance(const Vector2& rhs) const
			{
				return (*this - rhs).squaredLength();
			}

			/** Calculates the dot (scalar) product of this vector with another.
				@remarks
					The dot product can be used to calculate the angle between 2
					vectors. If both are unit vectors, the dot product is the
					cosine of the angle; otherwise the dot product must be
					divided by the product of the lengths of both vectors to get
					the cosine of the angle. This result can further be used to
					calculate the distance of a point from a plane.
				@param
					vec Vector with which to calculate the dot product (together
					with this one).
				@returns
					A float representing the dot product value.
			*/
			inline Real dotProduct(const Vector2& vec) const
			{
				return x * vec.x + y * vec.y;
			}

			/** Normalises the vector.
				@remarks
					This method normalises the vector such that it's
					length / magnitude is 1. The result is called a unit vector.
				@note
					This function will not crash for zero-sized vectors, but there
					will be no changes made to their components.
				@returns The previous length of the vector.
			*/
			inline Real normalise()
			{
				Real fLength = Math::Sqrt( x * x + y * y);

				// Will also work for zero-sized vectors, but will change nothing
				if ( fLength > 1e-08 )
				{
					Real fInvLength = Real_One / fLength;
					x *= fInvLength;
					y *= fInvLength;
				}

				return fLength;
			}



			/** Returns a vector at a point half way between this and the passed
				in vector.
			*/
			inline Vector2 midPoint( const Vector2& vec ) const
			{
				return Vector2(
					( x + vec.x ) * Real_Half,
					( y + vec.y ) * Real_Half );
			}

			/** Returns true if the vector's scalar components are all greater
				that the ones of the vector it is compared against.
			*/
			inline bool operator < ( const Vector2& rhs ) const
			{
				if( x < rhs.x && y < rhs.y )
					return true;
				return false;
			}

			/** Returns true if the vector's scalar components are all smaller
				that the ones of the vector it is compared against.
			*/
			inline bool operator > ( const Vector2& rhs ) const
			{
				if( x > rhs.x && y > rhs.y )
					return true;
				return false;
			}

			/** Sets this vector's components to the minimum of its own and the
				ones of the passed in vector.
				@remarks
					'Minimum' in this case means the combination of the lowest
					value of x, y and z from both vectors. Lowest is taken just
					numerically, not magnitude, so -1 < 0.
			*/
			inline void makeFloor( const Vector2& cmp )
			{
				if( cmp.x < x ) x = cmp.x;
				if( cmp.y < y ) y = cmp.y;
			}

			/** Sets this vector's components to the maximum of its own and the
				ones of the passed in vector.
				@remarks
					'Maximum' in this case means the combination of the highest
					value of x, y and z from both vectors. Highest is taken just
					numerically, not magnitude, so 1 > -3.
			*/
			inline void makeCeil( const Vector2& cmp )
			{
				if( cmp.x > x ) x = cmp.x;
				if( cmp.y > y ) y = cmp.y;
			}

			/** Generates a vector perpendicular to this vector (eg an 'up' vector).
				@remarks
					This method will return a vector which is perpendicular to this
					vector. There are an infinite number of possibilities but this
					method will guarantee to generate one of them. If you need more
					control you should use the Quaternion class.
			*/
			inline Vector2 perpendicular(void) const
			{
				return Vector2 (-y, x);
			}
			/** Calculates the 2 dimensional cross-product of 2 vectors, which results
				in a single floating point value which is 2 times the area of the triangle.
			*/
			inline Real crossProduct( const Vector2& rkVector ) const
			{
				return x * rkVector.y - y * rkVector.x;
			}
			/** Generates a new random vector which deviates from this vector by a
				given angle in a random direction.
				@remarks
					This method assumes that the random number generator has already
					been seeded appropriately.
				@param
					angle The angle at which to deviate in radians
				@param
					up Any vector perpendicular to this one (which could generated
					by cross-product of this vector and any other non-colinear
					vector). If you choose not to provide this the function will
					derive one on it's own, however if you provide one yourself the
					function will be faster (this allows you to reuse up vectors if
					you call this method more than once)
				@returns
					A random vector which deviates from this vector by angle. This
					vector will not be normalised, normalise it if you wish
					afterwards.
			*/
			inline Vector2 randomDeviant(
				Real angle) const
			{

				angle *=  Math::UnitRandom() * Math::TWO_PI;
				Real cosa = cos(angle);
				Real sina = sin(angle);
				return  Vector2(cosa * x - sina * y,
								sina * x + cosa * y);
			}

			/** Returns true if this vector is zero length. */
			inline bool isZeroLength(void) const
			{
				Real sqlen = (x * x) + (y * y);
				return (sqlen < (1e-06 * 1e-06));

			}

			/** As normalise, except that this vector is unaffected and the
				normalised vector is returned as a copy. */
			inline Vector2 normalisedCopy(void) const
			{
				Vector2 ret = *this;
				ret.normalise();
				return ret;
			}

			/** Calculates a reflection vector to the plane with the given normal .
			@remarks NB assumes 'this' is pointing AWAY FROM the plane, invert if it is not.
			*/
			inline Vector2 reflect(const Vector2& normal) const
			{
				return Vector2( *this - ( 2 * this->dotProduct(normal) * normal ) );
			}

			// special points
			static const Vector2 ZERO;
			static const Vector2 UNIT_X;
			static const Vector2 UNIT_Y;
			static const Vector2 NEGATIVE_UNIT_X;
			static const Vector2 NEGATIVE_UNIT_Y;
			static const Vector2 UNIT_SCALE;

			/** Function for writing to a stream.
			*/
			inline MATH_API friend std::ostream& operator <<
				( std::ostream& o, const Vector2& v )
			{
				o << "Vector2(" << v.x << ", " << v.y <<  ")";
				return o;
			}

		};
	}	// namespace math
}	// namespace framework
